A shark swam up to the fisherman, "bit the kayak, then briefly circled around the craft before swimming away," Spanheimer said.

The kayaker escaped injury and returned to shore.

Great white sharks are found more frequently along the Bay Area's ocean coast in the summer and fall, when the water is warmer. It was not known, however, whether it was a great white that bit the man's kayak.

The area where the kayaker was fishing was outside an area that surfers and swimmers frequent, Spanheimer said. As a precaution, however, Pacifica's Public Works Department will post signs at the beach warning people about the encounter, authorities said.